Improvement in rifling fire-arms



A. TRAUTH. f

Riing Fire-Arms.

UNITED STATES PATENT OFFICE.

A. TRAUTH, oF CHEMNITZ, sAXoNY.

IMPROVEMENT IN RIFLING FIRE-ARMS.`

Specification forming part of Letters Patent No. 50,433, dated October10, 1865.

v 3 is a diagram representing the shape of my rifle-grooves from one endof the barrel to the other.

Similar letters of reference indicate like parts.

This invention relates to ritle-grooves the transverse section of whichis not rectangular, but getting gradually smaller toward the outside,their form being dependent upon the kind and size of the lire-arm. Thedepth of these grooves decreases for a certain distance, and, togetherwith the depth, the width decreases, so that the advantages of thewedgeshaped grooves are obtained, and, where the depth does not alter,the width remains unchanged. The production of these grooves is muchsimpler and more correct than that of the wedge-shaped grooves, becausethe cutters used for cutting the same have to be moved only in a radialdirection in the proper proportion in order to produce the desiredresult. In the same manner the operation of polishing the improvedgrooves, which is difficult with Wedge-shaped grooves, is easilyaccomplished, and can be eifected simply by radially-expandingpolishing-jaws. As previously remarked,

vthe depth and length of these grooves gradually decrease up from thechamber up to a certain part, and then they continue to the muzzlewithout diminution.

In order to render the principle of breechloading without windagepracticable also for heavy ordnance with apowerful charge, where, if therifle-grooves are made in the usual manner, the lead ring would bestripped oif, I con tinue the grooves to the rear end of the chamber;and my system of riding is applicable to most all the devices forclosing the breech.

In using this method of ritling the lead ring cannot have a plaincylindrical surface; but it must be made with ribs to correspond to thegrooves, which consequently arc not cut out, but simply compressed asthe projectile passes out of the barrel. The grooves extend through thechamber with uniform width and depth, and then they decrease for acertain distance, when they continue to the muzzle with uniform depth.The ribs, having play in the grooves in the chamber, allow of pushingthe projectile forward to the inner end of said chamber, and for thisreason, and also because the motion of the projectile takes placeaccording to the grooves, and must not be converted from a rectilinearto the rotary motion, and because the power ordinarily required forcutting into the lead ring is not needed, the effect of a firearm rifledaccording to my invention is superior, and the lead ring is less liableto be destroyed than in ordinary rifled barrels. As soon as theprojectile has commenced its motion the ride-grooves begin to diminishand the lead ribs are compressed, so as to prevent Windage.

This kind of rifle-grooves is applicable to-all stationary cannons; butit cannot be used in field-ordnance, where the lead ribs of theprojectiles would be liable to be deformed by the jars to which they aresubjected in being transported over rugged ground, and ou account of thedeformation of said ribs the operation of loading could not be effectedwith the desired rapidity. With heavy charges, however, the simple leadribs might not be found of suflicient strength to sustain the strain towhich they will be subjected, and in this case I construct theprojectile with iron ribs, which are so low that they do not touch thebottom of the grooves, and act simply as guides, whereas the lead ring,with its ribs, produces the requisite gas-tight joint.

If desired, the bore of the barrel may be made to conform to the shapeof the grooves, being bored of uniform diameter to the end of thechamber, thence decreasing for a certain distance, and again of uniformdiameter to the muzzle.

The shape of my ride-grooves will be best understood from Fig. 2 of thedrawings, which shows a transverse section of the same, and

from Fig. 3, which shows a diagram thereof in the chamber of the barrelin a parallel direca longitudinal section. Fig. 2 shows the tation,thence diminishing in depth and Width peringv sides of the grooves, andby examining to about the middle of the length of the bar- Fig. 3 itwill be seen the grooves run parallel rel, (more or less,) and finallypassing on with from a to b, thence they decrease in depth to uniformdepth and width to the muzzle, subc, and thence their depth is uniformup to the stantially as and for the purpose described.

muzzle of the barrel.

I claim as new and desire to secure by Let- A' TRAUTH' ters Patent-Witnesses:

The production of rifle-grooves with a trape- THEODOR MARBACH,

zoidal cross-section, and extending through EDWARD WEIGEL.

